Dunta Robinson was cut by the Falcons, therefore he can sign whenever he wants as his contract was terminated whereas free agents contracts don't expire until the league year begins on Tuesday.

There is a 3 day negotiation period that the league approved this year to try to alleviate tampering concerns (even though we all know what really goes on), however no contracts can be signed and the players themselves aren't supposed to talk to teams, just teams and agents.

However, the league sent out a memo about not announcing anything until after real free agency starts so we may not get any leaks until the floodgates open Tuesday.

I thought no agreements/deals were allowed until free agency officially begins.

You can sign anyone who has been cut. They are in a totally different situation from a regular free agent.

If a team has cut a player, they no longer want the player. If a player is a free agent because his contract expired, the team he was on might still want that player. So, talking to that player is tampering.